Data packet transmission method and communication device

Abstract

The invention provides a data packet transmission method and a communication device. The method comprises the steps that first terminal equipment generates a first data packet; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a terminal-to-terminal U2U relay data packet or a terminal-to-network U2N relay data packet, or indicates the packet header format of the first data packet; and the first terminal device sends the first data packet to the relay device. Based on the method, the type of the data packet or the format of the data packet header can be indicated in the data packet, so that the relay equipment can process the data packet based on the type of the data packet or the format of the data packet header, and wrong information can be prevented from being analyzed from the data packet.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a data packet transmission method and a communication device. Background Art

[0002] Currently, there are two communication methods for sidelink relay, namely U2U (UE-to-UE) relay and U2N (UE-to-network) relay. U2U relay means that data and signaling can be transmitted between the original (source) user equipment (UE) and the destination (target) UE through a relay UE. U2N relay means that data and signaling can be transmitted between a UE and a base station through a relay UE. When a remote UE performs U2U relay communication and U2N relay communication through the same relay UE, the remote UE will establish two unicast connections with the relay UE respectively, that is, a U2U unicast connection and a U2N unicast connection.

[0003] When a remote UE performs U2U communication relay and U2N relay communication through the same relay UE, if a U2U relay data packet is incorrectly sent to the U2N unicast connection, the remote UE or the relay UE will process it as a U2N relay data packet, resulting in incorrect information being decoded. Or, when a remote UE performs U2U relay and U2N relay communication through the same relay UE, if a U2N relay data packet is incorrectly sent to the U2U unicast connection, the remote UE or the relay UE will process it as a U2U relay data packet, resulting in incorrect information being decoded from the data packet. Therefore, how to avoid decoding incorrect information from data packets is a technical problem that needs to be solved urgently at present. Summary of the Invention

[0004] This application provides a data packet transmission method and a communication device, which are beneficial to avoiding decoding incorrect information from data packets.

[0005] In a first aspect, this application provides a data packet transmission method. This method can be executed by a first terminal device, or by a module (such as a processor, a chip, or a chip system, etc.) applied to the first terminal device, or by a logical node, a logical module, or software that can implement all or part of the functions of the first terminal device. In this data packet transmission method:

[0006] The first terminal device generates a first data packet; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a terminal-to-terminal U2U relay data packet or a terminal-to-network U2N relay data packet, or indicates the header format of the first data packet; the first terminal device sends the first data packet to a relay device.

[0007] Based on the method described in the first aspect, it is possible to indicate the type of the data packet or the data packet header format in the data packet, so that the relay device can process the data packet based on the type of the data packet or the data packet header format, which helps to avoid parsing incorrect information from the data packet.

[0008] In a possible embodiment, the first indication information is located in the adaptation layer header of the first data packet. By making the first indication information located in the adaptation layer header of the first data packet, it is possible to reuse the reserved bit positions in the existing adaptation layer header, avoid the signaling overhead caused by introducing additional indication information, and also enable the relay device to correctly receive the first indication information by making the first indication information located in the adaptation layer header of the first data packet.

[0009] In a possible embodiment, the first terminal device receives a third data packet sent by the relay device; the third data packet carries second indication information, which indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the header format of the third data packet; the first terminal device reports the data in the third data packet to the Packet Data Convergence Protocol (PDCP) entity or discards the third data packet based on the second indication information.

[0010] Based on this possible embodiment, it is possible to indicate the type of the data packet or the data packet header format in the data packet, so that the first terminal device can process the data packet based on the type of the data packet or the data packet header format, which helps to avoid the first terminal device parsing incorrect information from the data packet.

[0011] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet.

[0012] In a possible embodiment, the first terminal device reporting the data in the third data packet to the PDCP entity or discarding the third data packet based on the second indication information includes:

[0013] If the second indication information does not match the unicast connection for receiving the third data packet, then discard the third data packet;

[0014] If the second indication information matches the unicast connection for receiving the third data packet, then report the data in the third data packet to the PDCP entity or discard the third data packet based on the local identifier and bearer identifier in the third data packet.

[0015] Based on this possible embodiment, the first terminal device can identify the data packet transmitted on the mismatched unicast connection and discard it, thereby avoiding the first terminal device parsing incorrect information from the third data packet.

[0016] In a possible embodiment, the first terminal device sends a request message to the relay device, where the request message is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of data packet or the header format of the data packet; the first terminal device enables the indication function between the first terminal device and the relay device.

[0017] Based on this possible embodiment, relay devices of old versions can also be compatible.

[0018] In a possible embodiment, the first terminal device enabling the indication function between the first terminal device and the relay device includes:

[0019] The first terminal device receives a response message from the relay device for the request message, where the response message indicates to enable the indication function between the first terminal device and the relay device; the first terminal device enables the indication function between the first terminal device and the relay device based on the response message.

[0020] Based on this possible embodiment, the indication function can be enabled bidirectionally.

[0021] In a possible embodiment, the first terminal device sending a request message to the relay device includes:

[0022] After establishing a first unicast connection and a second unicast connection between the first terminal device and the relay device, the first terminal device sends a request message to the relay device, where the first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or,

[0023] The first terminal device sends a direct communication request message for establishing a second unicast connection, where the direct communication request message carries the request message; or,

[0024] After establishing a first unicast connection between the first terminal device and the relay device and before establishing a second unicast connection between the first terminal device and the relay device, the first terminal device sends a request message to the relay device.

[0025] Based on this possible embodiment, the indication function can be enabled between devices that need to establish two unicast connections.

[0026] In a possible embodiment, after establishing a first unicast connection and a second unicast connection between the first terminal device and the relay device, the first terminal device enables the indication function between the first terminal device and the relay device, where the indication function is a function of indicating the type of data packet or the header format of the data packet, the first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or,

[0027] When the first terminal device sends a direct communication request message for establishing a second unicast connection to the relay device, the indication function between the first terminal device and the relay device is enabled; or,

[0028] When the first terminal device receives a direct communication acceptance message for establishing a second unicast connection sent by the relay device, the indication function between the first terminal device and the relay device is enabled.

[0029] Based on this possible embodiment, relay devices of old versions can also be compatible.

[0030] In a possible embodiment, the first terminal device reports the data in the third data packet or discards the third data packet to the PDCP entity based on the second indication information, including: the first terminal device determines that the third data packet comes from the relay device according to the source ID in the third data packet, and if a first unicast connection and a second unicast connection are established between the first terminal device and the relay device, the local identifier and the bearer identifier are determined from the third data packet based on the second indication information; the first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; the first terminal device reports the data in the third data packet or discards the third data packet to the corresponding PDCP entity based on the local identifier and the bearer identifier in the third data packet.

[0031] Based on this possible embodiment, the first terminal device can correctly process the data packets transmitted on the mismatched unicast connection and avoid packet loss.

[0032] In a second aspect, the present application provides a data packet transmission method. This method can be executed by the relay device, or can be executed by a module (such as a processor, a chip, or a chip system, etc.) applied to the relay device, and can also be implemented by a logical node, a logical module, or software that can implement all or part of the functions of the relay device. In this data packet transmission method:

[0033] The relay device receives a first data packet sent by the first terminal device; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a terminal-to-terminal U2U relay data packet or a terminal-to-network U2N relay data packet, or indicates the packet header format of the first data packet; the relay device forwards the data in the first data packet or discards the first data packet based on the first indication information.

[0034] In a possible embodiment, the first indication information is located in the adaptation layer header of the first data packet.

[0035] In a possible embodiment, the relay device forwards the data in the first data packet or discards the first data packet based on the first indication information, including:

[0036] If the first indication information does not match the unicast connection for receiving the first data packet, discard the first data packet;

[0037] If the first indication information matches the unicast connection for receiving the first data packet, forward the data in the first data packet or discard the first data packet based on the local identifier and bearer identifier in the first data packet.

[0038] In a possible embodiment, the relay device receives a second data packet; the relay device generates a third data packet based on the data in the second data packet, where the data in the third data packet is the same as the data in the second data packet; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the packet header format of the third data packet; the relay device sends the third data packet to the first terminal device.

[0039] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet.

[0040] In a possible embodiment, the relay device receives request information sent by the first terminal device, where the request information is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of the data packet or indicating the packet header format of the data packet;

[0041] The relay device enables the indication function between the first terminal device and the relay device based on the request information.

[0042] In a possible embodiment, the relay device sends response information for the request information to the first terminal device, and the response information indicates that the indication function between the first terminal device and the relay device is enabled.

[0043] In a possible embodiment, the relay device receives request information sent by the first terminal device, including:

[0044] After establishing a first unicast connection and a second unicast connection between the relay device and the first terminal device, the relay device receives request information sent by the first terminal device. The first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0045] The relay device receives a direct communication request message for establishing a second unicast connection sent by the first terminal device, and the direct communication request message carries the request information; or,

[0046] After establishing a first unicast connection between the relay device and the first terminal device and before establishing a second unicast connection between the relay device and the first terminal device, the relay device receives request information sent by the first terminal device.

[0047] In a possible embodiment, after establishing a first unicast connection and a second unicast connection between the relay device and the first terminal device, the relay device enables an indication function between the first terminal device and the relay device. The indication function is a function of indicating the type of data packet or the header format of the data packet. The first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0048] When the relay device receives a direct communication request message sent by the first terminal device for establishing a second unicast connection, the relay device enables the indication function between the first terminal device and the relay device; or,

[0049] When the relay device sends a direct communication acceptance message for establishing a second unicast connection to the first terminal device, the relay device enables the indication function between the first terminal device and the relay device.

[0050] In a possible embodiment, the relay device forwards the data in the first data packet or discards the first data packet based on the first indication information, including:

[0051] If it is determined based on the source ID in the first data packet that the first data packet comes from the first terminal device, and a first unicast connection and a second unicast connection are established between the first terminal device and the relay device, the relay device determines a local identifier and a bearer identifier from the first data packet based on the first indication information; the first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; the relay device forwards the data in the first data packet or discards the first data packet based on the local identifier and the bearer identifier in the first data packet.

[0052] For the beneficial effects of the second aspect, reference can be made to the beneficial effects of the first aspect, which will not be elaborated here.

[0053] In a third aspect, the present application provides a data packet transmission method. This method can be executed by the first terminal device, or by a module (such as a processor, a chip, or a chip system, etc.) applied to the first terminal device, or by a logical node, a logical module, or software that can implement all or part of the functions of the first terminal device. In this data packet transmission method:

[0054] The first terminal device receives a third data packet sent by the relay device; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the header format of the third data packet; the first terminal device reports the data in the third data packet to the Packet Data Convergence Protocol (PDCP) entity based on the second indication information or discards the third data packet.

[0055] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet.

[0056] In a possible embodiment, the first terminal device reports the data in the third data packet or discards the third data packet to the PDCP entity based on the second indication information, including:

[0057] If the second indication information does not match the unicast connection for receiving the third data packet, the third data packet is discarded; if the second indication information matches the unicast connection for receiving the third data packet, the data in the third data packet is reported to the PDCP entity or the third data packet is discarded based on the local identifier and bearer identifier in the third data packet.

[0058] In a possible embodiment, the first terminal device sends a request message to the relay device, where the request message is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of the data packet or the header format of the data packet; the first terminal device enables the indication function between the first terminal device and the relay device.

[0059] In a possible embodiment, the first terminal device enables the indication function between the first terminal device and the relay device, including:

[0060] The first terminal device receives a response message from the relay device for the request message, where the response message indicates to enable the indication function between the first terminal device and the relay device; the first terminal device enables the indication function between the first terminal device and the relay device based on the response message.

[0061] In a possible embodiment, the first terminal device sends a request message to the relay device, including:

[0062] After establishing a first unicast connection and a second unicast connection between the first terminal device and the relay device, the first terminal device sends a request message to the relay device, where the first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0063] The first terminal device sends a direct communication request message for establishing a second unicast connection to the relay device, where the direct communication request message carries the request message; or,

[0064] After establishing a first unicast connection between the first terminal device and the relay device and before establishing a second unicast connection between the first terminal device and the relay device, the first terminal device sends a request message to the relay device.

[0065] In a possible embodiment, after establishing a first unicast connection and a second unicast connection between the first terminal device and the relay device, the first terminal device enables an indication function between the first terminal device and the relay device. The indication function is a function of indicating the type of data packet or indicating the packet header format of the data packet. The first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0066] When the first terminal device sends a direct communication request message for establishing a second unicast connection to the relay device, the indication function between the first terminal device and the relay device is enabled; or,

[0067] When the first terminal device receives a direct communication acceptance message sent by the relay device for establishing a second unicast connection, the indication function between the first terminal device and the relay device is enabled.

[0068] In a possible embodiment, the first terminal device reports the data in the third data packet or discards the third data packet to the PDCP entity based on the second indication information, including:

[0069] The first terminal device determines that the third data packet comes from the relay device according to the source ID in the third data packet. If a first unicast connection and a second unicast connection are established between the first terminal device and the relay device, the local identifier and the bearer identifier are determined from the third data packet based on the second indication information. The first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device. The first terminal device reports the data in the third data packet or discards the third data packet to the corresponding PDCP entity based on the local identifier and the bearer identifier in the third data packet.

[0070] For the beneficial effects of the third aspect, reference can be made to the beneficial effects of the first aspect, which will not be elaborated here.

[0071] Fourthly, the present application provides a data packet transmission method. This method can be executed by the relay device, or by a module (such as a processor, a chip, or a chip system, etc.) applied to the relay device, or can also be implemented by a logical node, a logical module, or software that can implement all or part of the functions of the relay device. In this data packet transmission method:

[0072] The relay device receives a second data packet; the relay device generates a third data packet based on the data in the second data packet, and the data in the third data packet is the same as the data in the second data packet; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the packet header format of the third data packet; the relay device sends the third data packet to the first terminal device.

[0073] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet.

[0074] In a possible embodiment, the relay device receives request information sent by the first terminal device, where the request information is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of data packet or the header format of the data packet; the relay device enables the indication function between the first terminal device and the relay device based on the request information.

[0075] In a possible embodiment, the relay device sends response information for the request information to the first terminal device, and the response information indicates to enable the indication function between the first terminal device and the relay device.

[0076] In a possible embodiment, the relay device receives request information sent by the first terminal device, including:

[0077] After establishing a first unicast connection and a second unicast connection between the relay device and the first terminal device, the relay device receives request information sent by the first terminal device. The first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0078] The relay device receives a direct communication request message for establishing a second unicast connection sent by the first terminal device, and the direct communication request message carries the request information; or,

[0079] After establishing a first unicast connection between the relay device and the first terminal device and before establishing a second unicast connection between the relay device and the first terminal device, the relay device receives request information sent by the first terminal device.

[0080] In a possible embodiment, after establishing a first unicast connection and a second unicast connection between the relay device and the first terminal device, the relay device enables the indication function between the first terminal device and the relay device. The indication function is a function of indicating the type of data packet or the header format of the data packet. The first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0081] When the relay device receives a direct communication request message for establishing a second unicast connection sent by the first terminal device, it enables the indication function between the first terminal device and the relay device; or,

[0082] When the relay device sends a direct communication acceptance message for establishing a second unicast connection to the first terminal device, the indication function between the first terminal device and the relay device is enabled.

[0083] For the beneficial effects of the fourth aspect, reference can be made to the beneficial effects of the first aspect, which will not be elaborated here.

[0084] In a fifth aspect, the present application provides a communication device. For example, the communication device can be the first terminal device or a module applied to the first terminal device, such as a processor, a chip, or a chip system. It can also be a logical node, a logical module, or software that can implement all or part of the functions of the first terminal device. The communication device includes a module / unit for executing any one of the methods in the first aspect or the third aspect and its possible implementations.

[0085] In a sixth aspect, the present application provides a communication device. For example, the communication device can be the relay device or a module applied to the relay device, such as a processor, a chip, or a chip system. It can also be a logical node, a logical module, or software that can implement all or part of the functions of the relay device. The communication device includes a module / unit for executing any one of the methods in the second aspect or the fourth aspect and its possible implementations.

[0086] In a seventh aspect, the present application provides a communication device, including a processor. The processor is coupled to a memory, and the memory is used to store programs or instructions. When the programs or instructions are executed by the processor, the device executes the method of any one of the above first aspect to the fourth aspect.

[0087] In an eighth aspect, the present application provides a chip, which includes a processor and an interface. The processor is coupled to the interface. The interface is used to receive or output signals, and the processor is used to execute code instructions so that the chip executes the method of any one of the above first aspect to the fourth aspect.

[0088] In a ninth aspect, the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are called, the method of any one of the above first aspect to the fourth aspect is executed.

[0089] In a tenth aspect, the present application provides a computer program product, which includes computer program code. When the computer program code is run, the method of any one of the above first aspect to the fourth aspect is executed.

[0090] In a tenth aspect, the present application provides a communication system, which includes a communication device (such as a first terminal device) for executing the method of the first aspect above and a communication device (such as a relay device) for executing the second aspect above. Alternatively, the communication system includes a communication device (such as a first terminal device) for executing the method of the third aspect above and a communication device (such as a relay device) for executing the fourth aspect above. Description of the Drawings

[0091] Figure 1 FIG. is a schematic diagram of a user plane protocol stack for L2 U2U relay provided by the present application;

[0092] Figure 2 FIG. is a schematic diagram of a user plane protocol stack for L2 U2N relay provided by the present application;

[0093] Figure 3a FIG. is a schematic diagram of an adaptation layer header format for U2N relay data packets provided by the present application;

[0094] Figure 3b FIG. is a schematic diagram of an adaptation layer header format for U2U relay data packets provided by the present application;

[0095] Figure 4 FIG. is a schematic diagram of the architecture of a communication system provided by an embodiment of the present application;

[0096] Figures 5 to 7 FIG. is a schematic flowchart of a data packet transmission method provided by the present application;

[0097] Figure 8 and Figure 9 FIG. is a schematic diagram of the structure of a communication device provided by the present application. Detailed Embodiments

[0098] The following further describes in detail specific embodiments of the present application with reference to the drawings.

[0099] Terms such as "first" and "second" in the specification, claims and drawings of the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0100] References to "embodiments" in this specification mean that particular features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive of other embodiments. Those skilled in the art will understand explicitly and implicitly that the embodiments described herein can be combined with other embodiments.

[0101] In the present application, "at least one (item)" means one or more, "a plurality" means two or more, "at least two (items)" means two, three, or more than three, and "and / or" is used to describe the association relationship of associated objects, indicating that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist simultaneously. Here, A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one (item) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0102] "Sending information" in the present application can be understood as one device sending information to another device, or it can also be understood as a logical module within a device sending information to another logical module. For example, "the access network device sends information" can be understood as the access network device sending information to another device (such as a terminal), or it can be understood as logical module 1 in the access network device sending information to logical module 2 in the access network device.

[0103] "Receiving information" in the present application can be understood as one device receiving information from another device, or it can also be understood as a logical module within a device receiving information from another logical module. For example, "the access network device receives information" can be understood as the access network device receiving information from another device (such as a terminal), or it can be understood as logical module 1 in the access network device receiving information from logical module 2 in the access network device.

[0104] In this application, "sending information to... (such as a terminal)" or the relevant schematic in the drawings can be understood as the destination of the information being the terminal. This can include directly or indirectly sending information to the terminal. "Receiving information from... (such as a terminal)" or "receiving information sent from... (such as a terminal)" or "receiving the information sent by... (such as a terminal)", or the relevant schematic in the drawings can be understood as the source of the information being the terminal, which can include directly or indirectly receiving information from the terminal. Necessary processing may be performed on the information between the source and the destination of the information transmission, such as format conversion, etc., but the destination can understand the valid information from the source. Similar expressions in this application can be understood similarly and will not be elaborated here.

[0105] In order to avoid solving incorrect information, an embodiment of this application provides a data packet transmission method and a communication device. For the convenience of understanding the technical solution of this solution, some terms involved in this application will be explained below.

[0106] 1) Sidelink communication

[0107] In a wireless communication system, UEs can communicate with each other through the network, or can directly communicate with each other without relying on network devices. The interface between UEs is called the PC5 interface (the interface corresponding to sidelink is called PC5, and PC5 is the full name of the interface), similar to the Uu interface between a UE and a base station. The link between UEs is called the sidelink, and a typical application scenario of sidelink communication is vehicle-to-everything (V2X). In V2X, each vehicle is a UE, and UEs can directly transmit data with each other through the sidelink without going through the network, which can effectively reduce communication latency.

[0108] Broadcast, unicast, and multicast are supported on the sidelink. Unicast communication is similar to the data communication after establishing an RRC connection between a UE and a base station. A unicast connection needs to be established between two UEs first. After establishing the unicast connection, the two UEs can perform data communication based on the negotiated identifier, and the data can be encrypted or unencrypted. Compared with broadcast, in unicast communication, only the two UEs that have established the unicast connection can perform this unicast communication. A unicast communication on the sidelink corresponds to a pair of source layer-2 identifier (source L2 ID) and destination layer-2 identifier (destination L2 ID). The sub-header of each sidelink media access control protocol data unit (MAC PDU) will contain the source L2 ID and the destination L2 ID to enable the data to be transmitted to the correct receiving end.

[0109] 2) UE-to-UE relay

[0110] During UE-to-UE relay communication, there is a source UE, one or more target UEs, and one or more relay devices. There is a need for unicast communication between the source UE and the target UEs. The relay device can be used to enhance the sidelink coverage (e.g., the coverage signals between the source UE and the target UEs are poor or out of the coverage range) or capacity (e.g., the relay device is a very capable device). The source UE and the target UEs can transmit data and signaling through the relay device. In the L2-based relay method, the user plane data is relayed and forwarded below the packet data convergence protocol (PDCP) entity at the relay device side. In the L2 UE-to-UE relay architecture, the protocol stack of the user plane is as Figure 1 shown. An adaptation layer is added between the radio link control (RLC) layer and the PDCP entity in this protocol architecture. The main function of the adaptation layer is the multiplexing and demultiplexing of bearers, that is, it supports different bearers to be multiplexed onto one bearer or one bearer to be split into different bearers. The relay device assigns a local ID to each source UE and target UE and carries this local ID during the data packet routing process to indicate which UE the data comes from and which UE it is to be sent to.

[0111] 3) UE-to-network relay

[0112] During UE-to-network relay communication, data and signaling can be transmitted between the remote UE and the network device through a relay device. For example, the protocol stack of L2 UE-to-network relay is as Figure 2 shown. The data packets of the remote UE are relayed and forwarded below the PDCP layer of the relay device, that is, the relay device only maintains the RLC bearers for relaying, including RLC, media access control (MAC), and physical layer (PHY). Therefore, there is an end-to-end PDCP entity between the remote UE and the network device, but there is no end-to-end RLC, MAC, and PHY layer.

[0113] In addition, a sidelink relay adaptation protocol (SRAP) adaptation layer is added between the RLC layer and the PDCP entity in this protocol architecture. The main function of the SRAP layer is bearer multiplexing and demultiplexing, that is, it supports different bearers to be multiplexed onto one bearer or a bearer to be split into different bearers, and is used to distinguish the data of different Remote UEs. The adaptation layer in the protocol stack at both ends of the PC5 interface is called PC5-SRAP, and the adaptation layer in the protocol stack at both ends of the Uu interface is called Uu-SRAP.

[0114] 4) Adaptation layer header format of data packets

[0115] The adaptation layer header formats of UE-to-UE relay data packets and UE-to-network relay data packets are different. As Figure 3a shown, the adaptation layer header of the UE-to-network relay data packet includes a local ID (8 bits) and a BEARER ID (5 bits). As Figure 3b shown, the adaptation layer header of the UE-to-UE relay data packet includes two local IDs (16 bits) and a BEARER ID (5 bits).

[0116] To better understand the embodiments of this application, the system architecture involved in the embodiments of this application will be introduced first below:

[0117] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Global System of Mobile Communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, 5th generation (5G) system or New Radio (NR) and future communication systems, etc.

[0118] Figure 4 FIG. is a schematic diagram of the architecture of a communication system provided by an embodiment of the present application, and the solution in the present application is applicable to this communication system. This communication system may include UE1, UE2, relay device and network device. Figure 4 The numbers of UEs, relay devices and network devices in FIG. are only examples. The communication system may also include more UEs, relay devices and network devices, or include fewer UEs. The embodiments of the present application do not make any limitations.

[0119] Among them, UE1 communicates with the network device through the relay device. UE1 and the relay device communicate through a sidelink, and the corresponding interface is called the PC5 interface. The relay device and the network device communicate through the Uu interface. A first unicast connection can be established between UE1 and the relay device, and the first unicast connection is used for U2N relay communication. The first unicast connection can also be called a U2N unicast connection or a U2N relay unicast connection, etc. The embodiments of the present application do not make any limitations on the specific name of the unicast connection used for U2N relay communication. For ease of understanding, the U2N unicast connection will be used for description hereinafter.

[0120] Among them, UE1 communicates with UE2 through a relay device. The communication between UE1 and the relay device is through a sidelink, and the corresponding interface is called the PC5 interface. The communication between UE2 and the relay device is through a sidelink, and the corresponding interface is called the PC5 interface. A second unicast connection can be established between UE1 and the relay device, and a second unicast connection can also be established between the relay device and UE2. The second unicast connection is used for U2U relay communication. The second unicast connection can also be called a U2U unicast connection or a U2U relay unicast connection, etc. The embodiments of the present application do not limit the specific name of the unicast connection used for U2U relay communication. For ease of understanding, the U2U unicast connection will be described hereinafter.

[0121] That is to say, UE1 supports both U2U unicast connections and U2N unicast connections. UE2 supports both U2U unicast connections and U2N unicast connections.

[0122] 1) UE

[0123] UE can also be called a terminal, a terminal device, a mobile station, a mobile terminal, a mobile device, etc. UE can be widely applied to various scenarios, such as device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, autonomous driving, remote medical treatment, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, etc. UE can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a robotic arm, a smart home device, etc.

[0124] In the embodiments of the present application, the form of UE is not limited. The device for implementing the function of UE can be UE; it can also be a device capable of supporting UE to implement this function, such as a chip system. This device can be installed in UE or used in matching with UE.

[0125] 2) Network device

[0126] A network device can sometimes also be referred to as an access network node, access network entity, access node, or access network device, etc. It forms part of a communication system and is used to help a terminal achieve wireless access. In one possible scenario, the network device can be a base station, evolved NodeB (eNodeB), access point (AP), transmission reception point (TRP), next generation NodeB (gNB), next generation base station in a 6th generation (6G) mobile communication system, base station in a future mobile communication system, or an access node in a WiFi system, etc. The network device can be a macro base station, micro base station or indoor station, relay node or donor node, or a radio controller in a CRAN scenario. In one possible embodiment, the network device can also be a server, wearable device, vehicle or in-vehicle device, etc. For example, the network device in vehicle to everything (V2X) technology can be a road side unit (RSU). All or part of the functions of the network device in this application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (such as a cloud platform). The network device in this application can also be a logical node, logical module or software that can implement all or part of the network device functions.

[0127] In another possible scenario, multiple network devices cooperate to assist a terminal in achieving wireless access, and different network devices respectively implement some of the functions of a base station. For example, the network device can be a central unit (CU), distributed unit (DU), CU-control plane (CP), CU-user plane (UP), or radio unit (RU), etc. The CU and DU can be set separately, or they can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or radio frequency unit, such as included in a remote radio unit (RRU), active antenna unit (AAU), or remote radio head (RRH).

[0128] In different systems, the CU (or CU-CP and CU-UP), DU, or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, the CU may also be referred to as O-CU (Open CU), the DU may also be referred to as O-DU, the CU-CP may also be referred to as O-CU-CP, the CU-UP may also be referred to as O-CU-UP, and the RU may also be referred to as O-RU. For the convenience of description, in this application, the CU, CU-CP, CU-UP, DU, and RU are used as examples for description. Any unit among the CU (or CU-CP, CU-UP), DU, and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0129] In the embodiments of this application, the form of the network device is not limited. The device for implementing the functions of the network device may be the network device; it may also be a device capable of supporting the network device to implement such functions, such as a chip system. This device may be installed in the network device or used in matching with the network device.

[0130] The following further introduces the data packet transmission method and the communication device with reference to the accompanying drawings. It can be understood that in this application, the first terminal device and the relay device are used as examples of the execution subjects of this interaction schematic for illustration, but this application does not limit the execution subjects of the interaction schematic. For example, the first terminal device in the method provided in this application may also be a chip, a chip system, or a processor applied to the first terminal device, and may also be a logical node, a logical module, or software that can implement all or part of the first terminal device; the relay device in the method provided in this application may also be a chip, a chip system, or a processor applied to the relay device, and may also be a logical node, a logical module, or software that can implement all or part of the relay device.

[0131] Please refer to Figure 5 , Figure 5 which is a schematic flowchart of a data packet transmission method provided in the embodiments of this application. Among them:

[0132] 501. The first terminal device generates a first data packet; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a U2U relay data packet or a U2N relay data packet, or indicates the packet header format of the first data packet.

[0133] In the embodiments of this application, the first terminal device may be any terminal device having a unicast connection with the relay device.

[0134] Optionally, there are two unicast connections between the first terminal device and the relay device (such as a U2U unicast connection and a U2N unicast connection). For example, the first terminal device may be Figure 4 UE1 among

[0135] Optionally, there is a unicast connection (such as a U2U unicast connection or a U2N unicast connection) between the first terminal device and the relay device. For example, the first terminal device may be the UE2 in Figure 4 .

[0136] In a possible embodiment, the first indication information indicates that the header format of the first data packet is specifically: the first indication information indicates the adaptation layer header format of the first data packet. For example, the first indication information indicates whether the adaptation layer header format of the first data packet has two local IDs (16 bits) and one BEARER ID (5 bits), or has one local ID (8 bits) and one BEARER ID (5 bits).

[0137] In a possible embodiment, the first indication information is located in the adaptation layer header of the first data packet. Optionally, the first indication information is located in the reserved bit in the adaptation layer header of the first data packet. By making the first indication information located in the adaptation layer header of the first data packet, the reserved bits in the existing adaptation layer header can be reused, avoiding the signaling overhead caused by introducing additional indication information, and by making the first indication information located in the adaptation layer header of the first data packet, the relay device can also correctly receive the first indication information.

[0138] For example, the size of the first indication information is 1 bit. When the value of the first indication information is 0, it indicates a U2U relay data packet; when the value of the first indication information is 1, it indicates a U2N relay data packet. Or vice versa.

[0139] Again, for example, the size of the first indication information is 1 bit. When the value of the first indication information is 0, it indicates that the adaptation layer header format has two local IDs (16 bits) and one BEARER ID (5 bits); when the value of the first indication information is 1, it indicates that the adaptation layer header format has one local ID (8 bits) and one BEARER ID (5 bits). Or vice versa.

[0140] 502. The first terminal device sends a first data packet to the relay device. Correspondingly, the relay device receives the first data packet sent by the first terminal device.

[0141] For example, the first terminal device may send the first data packet to the relay device through a U2U unicast connection or a U2N unicast connection. Correspondingly, the relay device may receive the first data packet sent by the first terminal device through a U2U unicast connection or a U2N unicast connection.

[0142] 503. The relay device forwards the data in the first data packet or discards the first data packet based on the first indication information.

[0143] In the embodiments of the present application, there are two specific implementation manners for the relay device to forward the data in the first data packet or discard the first data packet based on the first indication information:

[0144] 1) If the first indication information does not match the unicast connection for receiving the first data packet, the relay device discards the first data packet; if the first indication information matches the unicast connection for receiving the first data packet, the relay device forwards the data in the first data packet or discards the first data packet based on the local identifier and bearer identifier in the first data packet.

[0145] In the embodiments of the present application, that the first indication information does not match the unicast connection for receiving the first data packet may also be understood as that the type of the first data packet indicated by the first indication information or the data packet header format does not match the unicast connection for receiving the first data packet. Alternatively, that the first indication information does not match the unicast connection for receiving the first data packet may also be understood as that the type of the first data packet indicated by the first indication information or the data packet header format does not match the source identifier (source ID) and / or destination identifier (destination ID) of the first data packet. A unicast connection corresponds to a pair of source identifier and destination identifier.

[0146] Similarly, that the first indication information matches the unicast connection for receiving the first data packet may also be understood as that the type of the first data packet indicated by the first indication information or the data packet header format matches the unicast connection for receiving the first data packet. Alternatively, that the first indication information matches the unicast connection for receiving the first data packet may also be understood as that the type of the first data packet indicated by the first indication information or the data packet header format matches the source identifier (source ID) and / or destination identifier (destination ID) of the first data packet.

[0147] In the embodiments of the present application, the specific implementation manner for the relay device to forward the data in the first data packet or discard the first data packet based on the local identifier and bearer identifier in the first data packet may be: The relay device matches the local identifier and bearer identifier in the first data packet with the adaptation layer configuration; if they match, the relay device forwards the data in the first data packet; if they do not match, the relay device discards the first data packet.

[0148] That is to say, in the first specific implementation manner, if the first data packet is transmitted on a mismatched unicast connection, the first data packet is discarded. If the first data packet is transmitted on the correct unicast connection, it is further determined whether to forward the data in the first data packet based on the local identifier and bearer identifier in the first data packet. Based on this specific implementation manner, the relay device can identify the data packet transmitted on the mismatched unicast connection and discard it, thereby avoiding the relay device from parsing incorrect information from the first data packet.

[0149] For example, taking the first terminal device as Figure 4 UE1 in it as an example. If the relay device receives the first data packet sent by UE1 on the U2U unicast connection, and the first indication information in the first data packet indicates a U2N relay data packet or indicates that the adaptation layer header format of the first data packet has one local ID (8 bits) and one BEARER ID (5 bits), then the relay device discards the first data packet. If the relay device receives the first data packet sent by UE1 on the U2U unicast connection, and the first indication information in the first data packet indicates a U2U relay data packet or indicates that the adaptation layer header format of the first data packet has two local IDs (16 bits) and one BEARER ID (5 bits), then the relay device determines whether these two local IDs and one BEARER ID match the adaptation layer configuration of the U2U relay communication. If they match, the relay device forwards the first data packet to UE2; if they do not match, the relay device discards the first data packet.

[0150] Optionally, for U2N relay communication, the relay device can obtain the adaptation layer configuration of the U2N relay communication from the network device, including the local ID and BEARER ID of UE1. For U2U relay communication, the relay device assigns local IDs to UE1 and UE2, obtains the BEARER ID from UE1 or UE2, or the relay device determines the BEARER ID according to the PC5 Config Index.

[0151] 2) If it is determined from the source ID in the first data packet that the first data packet comes from the first terminal device, and a U2N unicast connection and a U2U unicast connection are established between the first terminal device and the relay device, then the relay device determines the local identifier and the bearer identifier from the first data packet based on the first indication information; the relay device forwards the data in the first data packet or discards the first data packet based on the local identifier and the bearer identifier in the first data packet.

[0152] In the embodiments of this application, how the relay device forwards the data in the first data packet or discards the first data packet based on the local identifier and the bearer identifier in the first data packet can be seen in the previous description and will not be elaborated here.

[0153] That is to say, in the second specific implementation, the relay device does not care on which unicast connection the first data packet is transmitted. The relay device can determine, based on the source ID in the first data packet, that the terminal device sending the first data packet is the terminal device that has established a U2N unicast connection and a U2U unicast connection with the relay device. Since two unicast connections are established between the terminal device sending the first data packet and the relay device, the first data packet may be sent on a mismatched unicast connection. Therefore, the relay device can accurately determine the local identifier and the bearer identifier from the first data packet based on the first indication information. For the description of the mismatched unicast connection, please refer to the previous description and will not be elaborated here. The relay device determines whether to forward the data in the first data packet based on the local identifier and the bearer identifier in the first data packet. Based on this specific implementation, packet loss can be avoided, and the relay device can correctly process the data packets transmitted on the mismatched unicast connection.

[0154] Optionally, the specific implementation for the relay device to determine that the first data packet comes from the first terminal device based on the source ID in the first data packet is as follows: Determine the corresponding User Info ID according to the source ID, that is, it is determined that the first data packet comes from the first terminal device, and the source ID and the User Info ID have been associated during the establishment of the unicast connection. Exemplarily, the first terminal device establishes the first unicast connection with the relay device using the source ID #1 and the User Info ID #1, and the first terminal device establishes the second unicast connection with the relay device using the source ID #2 and the User Info ID #1. Then, the relay device can determine the User Info ID #1 corresponding to its source ID according to the source ID of the first data packet being source ID #1 or source ID #2.

[0155] For example, taking the first terminal device as Figure 4 UE1 in. The relay device receives the first data packet sent by UE1 on the U2U unicast connection. The first indication information in the first data packet indicates a U2N relay data packet or indicates that the adaptation layer header format of the first data packet is one with a local ID (8 bits) and a BEARER ID (5 bits). The relay device determines that the first data packet comes from UE1 according to the source ID carried in the packet MAC header. There is a U2U unicast connection and a U2N unicast connection between UE1 and the relay device. The relay device determines that the first 4 - 8 bits of the adaptation layer header of the first data packet are the BEARER ID and the first 9 - 16 bits are the local ID according to the first indication information. The relay device determines whether the local ID and the BEARER ID match the adaptation layer configuration of the U2N relay communication. If they match, the relay device forwards the data in the first data packet to the network device. If they do not match, the relay device discards the first data packet.

[0156] Optionally, an implementation for the relay device to forward the data of the first data packet to the network device is as follows: The PC5 SRAP entity of the relay device for U2U relay communication submits the data in the first data packet to the Uu SRAP entity, and the Uu SRAP entity of the relay device submits the data in the first data packet to the Uu RLC entity.

[0157] Optionally, for U2N relay communication, the relay device may obtain the adaptation layer configuration for U2N relay communication from the network device, including the local ID of UE1 and the BEARER ID. For U2U relay communication, the relay device assigns local IDs to UE1 and UE2, obtains the BEARER ID from UE1 or UE2, or the relay device determines the BEARER ID according to the PC5 Config Index.

[0158] In the embodiments of this application, the adaptation layer header formats of U2U relay data packets and U2N relay data packets are different. For example, as Figure 3a shown, the adaptation layer header of the U2N relay data packet includes a local identifier (local ID) (8 bits) and a bearer identifier (BEARER ID) (5 bits). As Figure 3b shown, the adaptation layer header of the U2U relay data packet includes two local IDs (16 bits) and a BEARER ID (5 bits). Where R represents the reserved bit. If the first indication information introduced in the embodiments of this application is in the adaptation layer, it may be included in the reserved bit. However, for old-version terminal devices (such as Rel-17 terminal devices), only U2N relay communication is supported, and U2U relay communication is not supported. When an old-version terminal device sends a data packet, there is no restriction on the value of the reserved bit, and the value of the reserved bit is not based on the unicast connection between the old-version terminal device and the relay device. The value of the reserved bit can be 0 or 1. For example, if the specific implementation for the relay device to forward the data in the first data packet or discard the first data packet based on the first indication information is the above first specific implementation, after the relay device receives the data packet sent by the old-version terminal device, the relay device will read the value of the reserved bit as the value of the first indication information. The old-version terminal device actually sends a U2N relay data packet on the U2N unicast connection, but the relay device may determine that the data packet sent by the old-version terminal device is a U2U relay data packet based on the value of the reserved bit, resulting in the relay device discarding the data packet. In a communication system, there may be both new-version UEs and old-version terminal devices. To be compatible with old-version terminal devices, the embodiments of this application provide the following three possible implementation manners:

[0159] 1) The first terminal device supports U2N relay communication and does not support U2U relay communication; the first indication information is located in the first reserved bit in the adaptation layer header of the first data packet, and the adaptation layer header includes the first reserved bit and the second reserved bit; if the first value is used to indicate that the type of the data packet is a U2N relay data packet or to indicate that the format of the adaptation layer header of the data packet is the adaptation layer header format of the U2N relay data packet, then the values of all the reserved bits in the adaptation layer header are the first value or the value of the first reserved bit is the first value.

[0160] That is to say, the first terminal device can be an old version of the terminal device (such as a Rel-17 terminal device). Among them, the first reserved bit can be any one of the reserved bits in the adaptation layer header. For example, assume that the first reserved bit in the adaptation layer header is the first reserved bit and the second reserved bit is the second reserved bit. Another example, assume that the first reserved bit in the adaptation layer header is the second reserved bit and the second reserved bit is the first reserved bit. There are the following two ways for the value of the second reserved bit in the adaptation layer header:

[0161] Way 1: The values of the first reserved bit and the second reserved bit are the same.

[0162] For example, if the bit value 0 indicates a U2N relay data packet or the adaptation layer header format has 1 local ID (8 bits) and one BEARER ID (5 bits), then the values of all the reserved bits in the adaptation layer header can be unified to 0, that is, the values of both the first reserved bit and the second reserved bit are 0. If the bit value 1 indicates a U2N relay data packet or the adaptation layer header format has 1 local ID (8 bits) and one BEARER ID (5 bits), then the values of all the reserved bits in the adaptation layer header can be unified to 1, that is, the values of both the first reserved bit and the second reserved bit are 1.

[0163] Way 2: The value of the second reserved bit is based on the implementation of the sending end and can be 0 or 1.

[0164] For example, if the bit value 0 indicates a U2N relay data packet or the adaptation layer header format has 1 local ID (8 bits) and one BEARER ID (5 bits), then the value of the first reserved bit in the adaptation layer header is 0, and the value of the second reserved bit is 0 or 1. If the bit value 1 indicates a U2N relay data packet or the adaptation layer header format has 1 local ID (8 bits) and one BEARER ID (5 bits), then the value of the first reserved bit in the adaptation layer header is 1, and the value of the second reserved bit is 0 or 1.

[0165] Through this possible implementation, different versions of terminal devices can have a consistent understanding of the first reserved bit, enabling the embodiments of the present application to be compatible with older versions of terminal devices.

[0166] 2) Enable the indication function between the first terminal device and the relay device through the display process. This indication function is for indicating the type of data packet or the header format of the data packet.

[0167] Specifically, the first terminal device can send a request message to the relay device. This request message is used to request the enabling of the indication function between the first terminal device and the relay device; the first terminal device enables the indication function between the first terminal device and the relay device. Correspondingly, the relay device can receive the request message sent by the first terminal device and enable the indication function between the first terminal device and the relay device based on this request message.

[0168] Among them, the first terminal device can first send a request message to the relay device and then enable the indication function between the first terminal device and the relay device. Or, the first terminal device can also first enable the indication function between the first terminal device and the relay device and then send a request message to the relay device. The embodiments of the present application do not make a limitation.

[0169] That is to say, after the first terminal device enables the indication function between the first terminal device and the relay device, the data packets sent by the first terminal device will carry indication information for indicating the type of data packet or the function of indicating the header format of the data packet. For older versions of terminal devices, since the indication function with the relay device will not be enabled. Therefore, the data packets sent by older versions of terminal devices will not carry indication information for indicating the type of data packet or the function of indicating the header format of the data packet, and the relay device also processes the data packets sent by older versions of terminal devices according to the existing mechanism. Therefore, based on this possible embodiment, older versions of terminal devices can also be compatible.

[0170] In a possible embodiment, the indication function can be enabled unidirectionally. That is, the relay device enables the indication function between the first terminal device and the relay device based on the request message sent by the first terminal device. However, the first terminal device does not need to be triggered by the relay device to enable the indication function, and the first terminal device can enable the indication function between the first terminal device and the relay device by itself.

[0171] In a possible embodiment, the indication function can be enabled bidirectionally. For example, the relay device may also send response information for the request information to the first terminal device, and the response information indicates to enable the indication function between the first terminal device and the relay device. Correspondingly, the specific implementation for the first terminal device to enable the indication function between the first terminal device and the relay device is as follows: The first terminal device receives the response information for the request information sent by the relay device; the first terminal device enables the indication function between the first terminal device and the relay device based on the response information.

[0172] That is to say, in this possible embodiment, the relay device enables the indication function between the first terminal device and the relay device based on the request information sent by the first terminal device. The first terminal device enables the indication function between the first terminal device and the relay device based on the response information sent by the relay device.

[0173] In a possible embodiment, the timing when the first terminal device sends the request information to the relay device, and the timing when the relay device receives the request information sent by the first terminal device can be one of the following timings:

[0174] Timing 1: After establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the first terminal device sends the request information to the relay device. Correspondingly, after establishing a U2N unicast connection and a U2U unicast connection between the relay device and the first terminal device, the relay device receives the request information sent by the first terminal device.

[0175] Optionally, the request information can be carried in a PC5 radio resource control (RRC) message.

[0176] That is to say, after establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the relay device enables the indication function.

[0177] Optionally, the first terminal device can also enable the indication function after establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device.

[0178] For example, assume that the indication function is enabled unidirectionally. After establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the first terminal device sends the request information to the relay device. And after establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the first terminal device enables the indication function. Correspondingly, after receiving the request information, the relay device enables the indication function based on the request information.

[0179] For another example, assume a two-way indication function. After establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the first terminal device sends a request message to the relay device. Correspondingly, after receiving the request message, the relay device enables the indication function based on the request message and sends a response message to the first terminal device. After receiving the response message, the first terminal device enables the indication function based on the response message.

[0180] Timing 2: The first terminal device sends a direct communication request message for establishing a second unicast connection to the relay device, and the direct communication request message carries the request information. Correspondingly, the relay device receives the direct communication request message sent by the first terminal device for establishing a second unicast connection, and the direct communication request message carries the request information.

[0181] That is to say, when establishing a second unicast connection between the first terminal device and the relay device, the relay device enables the indication function.

[0182] Optionally, the first terminal device may also enable the indication function when establishing a second unicast connection with the relay device.

[0183] For example, assume a one-way indication function. A U2N unicast connection is first established between the first terminal device and the relay device. When the first terminal device establishes a U2U unicast connection with the relay device, the first terminal device sends a request message to the relay device, and the request message may be included in the direct communication request message. And the first terminal device enables the indication function when establishing the U2U unicast connection. Correspondingly, after receiving the request message, the relay device enables the indication function based on the request message.

[0184] For another example, assume a two-way indication function. A U2N unicast connection is first established between the first terminal device and the relay device. When the first terminal device establishes a U2U unicast connection with the relay device, the first terminal device sends a request message to the relay device, and the request message may be included in the direct communication request message. Correspondingly, after receiving the request message, the relay device enables the indication function based on the request message and sends a response message to the first terminal device, and the response message may be included in the direct communication acceptance message. After receiving the response message, the first terminal device enables the indication function based on the response message.

[0185] Timing 3: After establishing the first unicast connection between the first terminal device and the relay device and before establishing the second unicast connection between the first terminal device and the relay device, the first terminal device sends a request message to the relay device. Correspondingly, after establishing the first unicast connection between the relay device and the first terminal device and before establishing the second unicast connection between the relay device and the first terminal device, the relay device receives the request message sent by the first terminal device.

[0186] Optionally, the request information may be carried in the PC5 RRC message.

[0187] That is, after establishing a first unicast connection between the first terminal device and the relay device and before establishing a second unicast connection between the first terminal device and the relay device, the relay device enables the indication function.

[0188] Optionally, the first terminal device may also enable the indication function after establishing a first unicast connection with the relay device and before establishing a second unicast connection with the relay device.

[0189] For example, assume a unidirectional indication function is enabled. A U2N unicast connection is first established between the first terminal device and the relay device. Before establishing a U2U unicast connection with the relay device, a request information is sent to the relay device. And the first terminal device enables the indication function after establishing a U2N unicast connection with the relay device and before establishing a U2U unicast connection with the relay device. Correspondingly, after receiving the request information, the relay device enables the indication function based on the request information.

[0190] Another example, assume a bidirectional indication function is enabled. A U2N unicast connection is first established between the first terminal device and the relay device. Before establishing a U2U unicast connection, the first terminal device sends a request information to the relay device. Correspondingly, after receiving the request information, the relay device enables the indication function based on the request information and sends a response information to the first terminal device. After receiving the response information, the first terminal device enables the indication function based on the response information.

[0191] 3) The indication function between the first terminal device and the relay device is enabled by default.

[0192] The timing when the first terminal device and the relay device enable the indication function between the first terminal device and the relay device by default may be one of the following timings:

[0193] Timing 1: After establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the first terminal device enables the indication function between the first terminal device and the relay device. Correspondingly, after establishing a U2N unicast connection and a second unicast connection between the relay device and the first terminal device, the relay device enables the indication function between the first terminal device and the relay device.

[0194] That is, after establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the first terminal device and the relay device enable the indication function.

[0195] Timing 2: When the first terminal device sends a direct communication request message for establishing a second unicast connection to the relay device, the indication function between the first terminal device and the relay device is enabled. Correspondingly, when the relay device receives the direct communication request message sent by the first terminal device for establishing a second unicast connection, the indication function between the first terminal device and the relay device is enabled.

[0196] That is to say, when establishing a second unicast connection between the first terminal device and the relay device, the first terminal device and the relay device enable the indication function.

[0197] For example, a U2N unicast connection is first established between the first terminal device and the relay device. When establishing a U2U unicast connection between the first terminal device and the relay device, the first terminal device and the relay device enable the indication function between the first terminal device and the relay device.

[0198] Timing 3: When the first terminal device receives the direct communication acceptance message sent by the relay device for establishing a second unicast connection, the indication function between the first terminal device and the relay device is enabled. Correspondingly, when the relay device sends the direct communication acceptance message for establishing a second unicast connection to the first terminal device, the indication function between the first terminal device and the relay device is enabled.

[0199] That is to say, when the establishment of the second unicast connection between the first terminal device and the relay device is successful, the first terminal device and the relay device enable the indication function.

[0200] For example, a U2N unicast connection is first established between the first terminal device and the relay device. Before establishing a U2U unicast connection between the first terminal device and the relay device, the first terminal device and the relay device enable the indication function between the first terminal device and the relay device.

[0201] It can be seen that based on Figure 5 the described method, the type of the data packet or the data packet header format can be indicated in the data packet, so that the relay device can process the data packet based on the type of the data packet or the data packet header format, which is beneficial to avoiding parsing incorrect information from the data packet.

[0202] Please refer to Figure 6 , Figure 6 which is a schematic flowchart of a data packet transmission method provided by an embodiment of the present application. Among them:

[0203] 601. The relay device receives a second data packet.

[0204] Among them, the second data packet may come from a network device or a second terminal device. The second terminal device is a terminal device that has established a U2U unicast connection with the relay device. For example, the second terminal device may be Figure 4UE1 or UE2 among them.

[0205] 602. The relay device generates a third data packet based on the data in the second data packet, and the data in the third data packet is the same as the data in the second data packet; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the packet header format of the third data packet.

[0206] That is to say, after receiving a second data packet, the relay device can generate a third data packet to forward the data in the second data packet.

[0207] 603. The relay device sends the third data packet to the first terminal device. Correspondingly, the first terminal device receives the third data packet sent by the relay device.

[0208] In the embodiments of the present application, the first terminal device is a terminal device that has established a unicast connection with the relay device. The relay device can send the third data packet to the first terminal device through a U2U unicast connection or a U2N unicast connection. Correspondingly, the first terminal device can receive the third data packet sent by the relay device through a U2U unicast connection or a U2N unicast connection.

[0209] Optionally, there are two unicast connections (such as a U2U unicast connection and a U2N unicast connection) between the first terminal device and the relay device. For example, the relay device receives the second data packet sent by the network device or UE2. The first terminal device can be Figure 4 UE1 among them.

[0210] Optionally, there is one unicast connection (such as a U2U unicast connection or a U2N unicast connection) between the first terminal device and the relay device. For example, the relay device receives the second data packet sent by UE1. The first terminal device can be Figure 4 UE2 among them.

[0211] In a possible embodiment, the second indication information indicating the packet header format of the third data packet specifically is: the second indication information indicates the adaptation layer header format of the third data packet. For example, the second indication information indicates whether the adaptation layer header format of the third data packet has two local IDs (16 bits) and one BEARER ID (5 bits), or has one local ID (8 bits) and one BEARER ID (5 bits).

[0212] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet. Optionally, the second indication information is located in the reserved bit in the adaptation layer header of the first data packet. By making the second indication information located in the adaptation layer header of the first data packet, it is possible to reuse the reserved bits in the existing adaptation layer header and avoid the signaling overhead caused by introducing additional indication information.

[0213] For example, the size of the second indication information is 1 bit. When the value of the second indication information is 0, it indicates a U2U relay data packet; when the value of the second indication information is 1, it indicates a U2N relay data packet. Or vice versa.

[0214] For another example, the size of the second indication information is 1 bit. When the value of the second indication information is 0, it indicates that the adaptation layer header format has two local IDs (16 bits) and one BEARER ID (5 bits); when the value of the second indication information is 1, it indicates that the adaptation layer header format has one local ID (8 bits) and one BEARER ID (5 bits). Or vice versa.

[0215] 604. The first terminal device reports the data in the third data packet to the PDCP entity or discards the third data packet based on the second indication information.

[0216] In the embodiments of the present application, there are two specific implementation manners for the first terminal device to report the data in the third data packet to the PDCP entity or discard the third data packet based on the second indication information:

[0217] 1) If the second indication information does not match the unicast connection for receiving the third data packet, the first terminal device discards the third data packet; if the second indication information matches the unicast connection for receiving the third data packet, the first terminal device reports the data in the third data packet to the PDCP entity or discards the third data packet based on the local identifier and bearer identifier in the third data packet.

[0218] In the embodiments of the present application, that the second indication information does not match the unicast connection for receiving the third data packet can also be understood as that the type of the third data packet indicated by the second indication information or the data packet header format does not match the unicast connection for receiving the third data packet. Or, that the second indication information does not match the unicast connection for receiving the third data packet can also be understood as that the type of the third data packet indicated by the second indication information or the data packet header format does not match the source identifier (source ID) and / or destination identifier (destination ID) of the third data packet. A unicast connection corresponds to a pair of source identifier and destination identifier.

[0219] Similarly, the second indication information matches the unicast connection for receiving the third data packet, which can also be understood as that the type of the third data packet or the data packet header format indicated by the second indication information matches the unicast connection for receiving the third data packet. Alternatively, the second indication information matches the unicast connection for receiving the third data packet, which can also be understood as that the type of the third data packet or the data packet header format indicated by the second indication information matches the source ID and / or destination ID of the third data packet.

[0220] In the embodiments of the present application, the specific implementation manner in which the first terminal device reports the data in the third data packet or discards the third data packet to the PDCP entity based on the local ID and the bearer ID in the third data packet may be: the first terminal device matches the local ID and the bearer ID in the third data packet with the adaptation layer configuration; if they match, the first terminal device reports the data in the third data packet to the PDCP entity; if they do not match, the first terminal device discards the third data packet.

[0221] That is to say, in the first specific implementation manner, if the third data packet is transmitted on a mismatched unicast connection, the third data packet is discarded. If the third data packet is transmitted on the correct unicast connection, it is further determined whether to report the data in the third data packet to the PDCP entity based on the local ID and the bearer ID in the third data packet. Based on this specific implementation manner, the first terminal device can identify the data packet transmitted on the mismatched unicast connection and discard it, thereby preventing the first terminal device from parsing incorrect information from the third data packet.

[0222] For example, taking the first terminal device as Figure 4 UE1 in

[0223] Optionally, for U2N relay communication, UE1 may obtain the adaptation layer configuration of U2N relay communication from the network device, including the local ID of UE1 and the BEARER ID. For U2U relay communication, UE1 obtains the local IDs of UE1 and UE2 from the relay device, UE1 determines the BEARER ID by itself or obtains the BEARER ID from UE2, or UE1 determines the BEARER ID according to the PC5 Config Index.

[0224] 2) If the first terminal device determines that the third data packet comes from the relay device according to the source ID in the third data packet, and a U2N unicast connection and a U2U unicast connection are established between the first terminal device and the relay device, the first terminal device determines the local identifier and the bearer identifier from the third data packet based on the second indication information; the first terminal device reports the data in the third data packet to the corresponding PDCP entity or discards the third data packet based on the local identifier and the bearer identifier in the third data packet.

[0225] In the embodiments of the present application, the corresponding PDCP entity may be understood as the PDCP entity corresponding to the service data type carried in the third data packet. Exemplarily, if the service data carried in the third data packet is U2N relay service data, the corresponding PDCP entity is the PDCP entity used by the first terminal device for U2N relay communication; if the service data carried in the third data packet is U2U relay service data, the corresponding PDCP entity is the PDCP entity used by the first terminal device for U2U relay communication.

[0226] That is to say, in the second specific implementation manner, the first terminal device does not care on which unicast connection the third data packet is transmitted. The first terminal device may determine that the relay device sending the third data packet is the device that has established a U2N unicast connection and a U2U unicast connection with the relay device based on the source ID in the third data packet. Since two unicast connections are established between the relay device sending the third data packet and the first terminal device, the third data packet may be sent on a mismatched unicast connection. Therefore, the first terminal device can accurately determine the local identifier and the bearer identifier from the third data packet based on the second indication information; for the description of the mismatched unicast connection, please refer to the description in the previous text and will not be elaborated here. The first terminal device reports the data in the third data packet to the corresponding PDCP entity or discards the third data packet based on the local identifier and the bearer identifier in the third data packet. Based on this specific implementation manner, the first terminal device can correctly process the data packet transmitted on the mismatched unicast connection and avoid packet loss.

[0227] Optionally, the specific implementation of the first terminal device determining that the third data packet comes from the relay device based on the source ID in the third data packet is as follows: determining the corresponding User Info ID according to the source ID, that is, determining that the third data packet comes from the relay device. The source ID and the User Info ID have been associated during the establishment of the unicast connection. Exemplarily, the relay device establishes a first unicast connection with the first terminal device using source ID #1 and User Info ID #1, and the relay device establishes a second unicast connection with the first terminal device using source ID #2 and User Info ID #1. Then, the first terminal device can determine that the User Info ID corresponding to its source ID is User Info ID #1 according to the source ID of the third data packet being source ID #1 or source ID #2.

[0228] For example, taking the first terminal device as Figure 4 UE1 in it as an example. UE1 receives the third data packet sent by the relay device on the U2U unicast connection. The second indication information in the third data packet indicates a U2N relay data packet or indicates that the adaptation layer header format of the third data packet has a local ID (8 bits) and a BEARER ID (5 bits). UE1 determines that the third data packet comes from the relay device according to the source ID carried in the packet MAC header. There is a U2U unicast connection and a U2N unicast connection between the relay device and the relay device. UE1 determines that the first 4 - 8 bits of the adaptation layer header of the third data packet are the BEARER ID and the first 9 - 16 bits are the local ID according to the second indication information. UE1 determines whether the local ID and the BEARER ID match the adaptation layer configuration for U2N relay communication. If they match, UE1 reports the data in the third data packet to the PDCP entity for U2N relay communication. If they do not match, UE1 discards the third data packet.

[0229] Optionally, one implementation of UE1 reporting the data in the third data packet to the PDCP entity for U2N relay communication is as follows: The PC5 SRAP entity for U2U relay communication of UE1 delivers the data in the third data packet to the PC5 SRAP entity for U2N relay communication of UE1, and the PC5 SRAP entity for U2N relay communication of UE1 delivers the data in the third data packet to the PDCP entity for U2N relay communication.

[0230] Optionally, for U2N relay communication, UE1 may obtain the adaptation layer configuration for U2N relay communication from a network device, including the local ID of UE1 and the BEARER ID. For U2U relay communication, UE1 obtains the local IDs of UE1 and UE2 from a relay device. UE1 determines the BEARER ID by itself, obtains the BEARER ID from UE2, or determines the BEARER ID according to the PC5 Config Index.

[0231] In a communication system, there may be both new version UEs and old version terminal devices. To be compatible with old version terminal devices, the embodiments of this application provide the following three possible implementation manners:

[0232] 1) The relay device supports U2N relay communication and does not support U2U relay communication; the second indication information is located in the first reserved bit in the adaptation layer header of the third data packet. The adaptation layer header includes the first reserved bit and the second reserved bit; if the first value is used to indicate that the type of the data packet is a U2N relay data packet or to indicate that the format of the adaptation layer header of the data packet is the adaptation layer header format of a U2N relay data packet, then the values of all the reserved bits in the adaptation layer header are the first value or the value of the first reserved bit is the first value.

[0233] That is to say, the relay device may be an old version terminal device (such as a Rel-17 terminal device). Among them, the first reserved bit may be any one of the reserved bits in the adaptation layer header. For example, assume that the first reserved bit in the adaptation layer header is the first reserved bit and the second reserved bit is the second reserved bit. Another example, assume that the first reserved bit in the adaptation layer header is the second reserved bit and the second reserved bit is the first reserved bit. There are the following two ways for the value of the second reserved bit in the adaptation layer header:

[0234] Way 1: The values of the first reserved bit and the second reserved bit are the same.

[0235] Way 2: The value of the second reserved bit is based on the implementation of the sending end and can take 0 or 1.

[0236] Through this possible implementation manner, different version terminal devices can have the same understanding of the first reserved bit, so that the embodiments of this application can be compatible with old version terminal devices.

[0237] 2) Enable the indication function between the first terminal device and the relay device through a display process. The indication function is a function of indicating the type of the data packet or the format of the packet header of the data packet.

[0238] Specifically, the first terminal device may send a request message to the relay device, where the request message is used to request to enable the indication function between the first terminal device and the relay device; the first terminal device enables the indication function between the first terminal device and the relay device. Correspondingly, the relay device may receive the request message sent by the first terminal device and enable the indication function between the first terminal device and the relay device based on the request message.

[0239] Among them, the first terminal device may first send a request message to the relay device and then enable the indication function between the first terminal device and the relay device. Alternatively, the first terminal device may also first enable the indication function between the first terminal device and the relay device and then send a request message to the relay device, which is not limited in the embodiments of the present application.

[0240] That is to say, after the relay device enables the indication function between the first terminal device and the relay device, the data packets sent by the relay device will carry indication information for indicating the type of the data packet or the function of indicating the packet header format of the data packet. For old-version relay devices, since the indication function between the relay devices will not be enabled. Therefore, the data packets sent by the old-version relay devices will not carry indication information for indicating the type of the data packet or the function of indicating the packet header format of the data packet, and the first terminal device also processes the data packets sent by the old-version relay devices according to the existing mechanism. Therefore, based on this possible implementation manner, old-version relay devices can also be compatible.

[0241] In a possible embodiment, the indication function may be enabled unidirectionally. That is, the relay device enables the indication function between the first terminal device and the relay device based on the request message sent by the first terminal device. However, the first terminal device does not need to be triggered by the relay device to enable the indication function, and the first terminal device can enable the indication function between the first terminal device and the relay device by itself.

[0242] In a possible embodiment, the indication function may be enabled bidirectionally. For example, the relay device may also send a response message to the first terminal device for the request message, where the response message indicates to enable the indication function between the first terminal device and the relay device. Correspondingly, the specific implementation manner for the first terminal device to enable the indication function between the first terminal device and the relay device is: the first terminal device receives the response message sent by the relay device for the request message; the first terminal device enables the indication function between the first terminal device and the relay device based on the response message.

[0243] That is to say, in this possible embodiment, the relay device enables the indication function between the first terminal device and the relay device based on the request message sent by the first terminal device. The first terminal device enables the indication function between the first terminal device and the relay device based on the response message sent by the relay device.

[0244] In a possible embodiment, the timing for the first terminal device to send a request message to the relay device and the timing for the relay device to receive the request message sent by the first terminal device may be one of the following timings:

[0245] Timing 1: After establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the first terminal device sends a request message to the relay device. Correspondingly, after establishing a U2N unicast connection and a U2U unicast connection between the relay device and the first terminal device, the relay device receives the request message sent by the first terminal device.

[0246] Optionally, the request message may be carried in a PC5 radio resource control (RRC) message.

[0247] That is to say, after establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device, the relay device enables the indication function.

[0248] Optionally, the first terminal device may also enable the indication function after establishing a U2N unicast connection and a U2U unicast connection between the first terminal device and the relay device.

[0249] Timing 2: The first terminal device sends a direct communication request message for establishing a second unicast connection to the relay device, and the direct communication request message carries the request message. Correspondingly, the relay device receives the direct communication request message for establishing a second unicast connection sent by the first terminal device, and the direct communication request message carries the request message.

[0250] That is to say, when establishing a second unicast connection between the first terminal device and the relay device, the relay device enables the indication function.

[0251] Optionally, the first terminal device may also enable the indication function when establishing a second unicast connection between the first terminal device and the relay device.

[0252] Timing 3: After establishing a first unicast connection between the first terminal device and the relay device and before establishing a second unicast connection between the first terminal device and the relay device, the first terminal device sends a request message to the relay device. Correspondingly, after establishing a first unicast connection between the relay device and the first terminal device and before establishing a second unicast connection between the relay device and the first terminal device, the relay device receives the request message sent by the first terminal device.

[0253] Optionally, the request message may be carried in a PC5 radio resource control (RRC) message.

[0254] That is to say, after establishing a first unicast connection between the first terminal device and the relay device and before establishing a second unicast connection between the first terminal device and the relay device, the relay device enables the indication function.

[0255] Optionally, the first terminal device may also enable the indication function after establishing the first unicast connection with the relay device and before establishing the second unicast connection with the relay device.

[0256] 3) By default, enable the indication function between the first terminal device and the relay device.

[0257] The timing for the first terminal device and the relay device to default enable the indication function between the first terminal device and the relay device may be one of the following timings:

[0258] Timing 1: After the first terminal device establishes a U2N unicast connection and a U2U unicast connection with the relay device, enable the indication function between the first terminal device and the relay device. Correspondingly, after the relay device establishes a U2N unicast connection and a second unicast connection with the first terminal device, enable the indication function between the first terminal device and the relay device.

[0259] That is to say, after the first terminal device and the relay device establish a U2N unicast connection and a U2U unicast connection, the first terminal device and the relay device enable the indication function.

[0260] Timing 2: When the first terminal device sends a direct communication request message for establishing the second unicast connection to the relay device, enable the indication function between the first terminal device and the relay device. Correspondingly, when the relay device receives the direct communication request message sent by the first terminal device for establishing the second unicast connection, enable the indication function between the first terminal device and the relay device.

[0261] That is to say, when establishing the second unicast connection between the first terminal device and the relay device, the first terminal device and the relay device enable the indication function.

[0262] Timing 3: When the first terminal device receives the direct communication acceptance message sent by the relay device for establishing the second unicast connection, enable the indication function between the first terminal device and the relay device. Correspondingly, when the relay device sends the direct communication acceptance message for establishing the second unicast connection to the first terminal device, enable the indication function between the first terminal device and the relay device.

[0263] That is to say, when the second unicast connection between the first terminal device and the relay device is successfully established, the first terminal device and the relay device enable the indication function.

[0264] Figure 6 For specific examples of three possible implementation manners proposed in the corresponding embodiments to be compatible with old version terminal devices, refer to Figure 5 the corresponding description in the corresponding embodiments, inFigure 6 The corresponding embodiments will not be described in detail again.

[0265] It can be seen that based on Figure 6 the method described above, it is possible to indicate the type of the data packet or the data packet header format in the data packet, so that the first terminal device can process the data packet based on the type of the data packet or the data packet header format, which helps to avoid the first terminal device parsing incorrect information from the data packet.

[0266] Figure 5 The corresponding embodiments can be combined with Figure 6 the corresponding embodiments. For example, please refer to Figure 7 , Figure 7 which is a schematic flowchart of a data packet transmission method provided by an embodiment of the present application. Among them:

[0267] 701. The first terminal device generates a first data packet; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a U2U relay data packet or a U2N relay data packet, or indicates the header format of the first data packet.

[0268] 702. The first terminal device sends the first data packet to the relay device. Correspondingly, the relay device receives the first data packet sent by the first terminal device.

[0269] 703. The relay device forwards the data in the first data packet based on the first indication information or discards the first data packet.

[0270] For the descriptions of steps 701 to 703, please refer to Figure 5 the descriptions of steps 501 to 503 therein, which will not be elaborated here.

[0271] 704. The relay device receives a second data packet.

[0272] 705. The relay device generates a third data packet based on the data in the second data packet, and the data in the third data packet is the same as the data in the second data packet; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the header format of the third data packet.

[0273] 706. The relay device sends the third data packet to the first terminal device. Correspondingly, the first terminal device receives the third data packet sent by the relay device.

[0274] 707. The first terminal device reports the data in the third data packet to the PDCP entity based on the second indication information or discards the third data packet.

[0275] For the descriptions of steps 704 to 707, please refer toFigure 6 The descriptions of steps 601 to 604 in [reference] are not elaborated herein. Steps 701 to 703 may be executed before steps 704 to 707, or steps 701 to 703 may be executed after steps 704 to 707. The embodiments of the present application do not make any limitations in this regard.

[0276] It can be seen that based on Figure 7 the described method, it is possible to indicate the type of the data packet or the data packet header format in the data packet, so that the first terminal device and the relay device can process the data packet based on the type of the data packet or the data packet header format, which is beneficial to avoiding the first terminal device and the relay device from parsing incorrect information from the data packet.

[0277] The present application provides a communication device, which can be used to implement the functions of the above-mentioned first terminal device or relay device. The communication device may be the first terminal device or the relay device. The communication device includes modules or units corresponding one by one to the methods / operations / steps / actions executed by the first terminal device or the relay device in the above method embodiments. The unit may be a hardware circuit, software, or a combination of a hardware circuit and software. Please refer to Figure 8 , Figure 8 FIG. shows a schematic structural diagram of a communication device 800 according to an embodiment of the present application. The communication device 800 may include an interface unit 801 and a processing unit 802. The processing unit 802 is configured to process signaling and / or data, and the signaling and / or data may be data received by the interface unit 801. The processed signaling and / or data may also be sent by the interface unit 801;

[0278] In one implementation, when the communication device 800 is the first terminal device, where:

[0279] The processing unit 802 is configured to generate a first data packet; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a terminal-to-terminal U2U relay data packet or a terminal-to-network U2N relay data packet, or indicates the header format of the first data packet;

[0280] The interface unit 801 is configured to send the first data packet to the relay device.

[0281] In a possible embodiment, the first indication information is located in the adaptation layer header of the first data packet.

[0282] In a possible embodiment, the interface unit 801 is further configured to receive a third data packet sent by a relay device; the third data packet carries second indication information, where the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the header format of the third data packet; the processing unit 802 is further configured to report the data in the third data packet to a Packet Data Convergence Protocol (PDCP) entity or discard the third data packet based on the second indication information.

[0283] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet.

[0284] In a possible embodiment, the processing unit 802 reporting the data in the third data packet to the PDCP entity or discarding the third data packet based on the second indication information includes: if the second indication information does not match the unicast connection for receiving the third data packet, discarding the third data packet; if the second indication information matches the unicast connection for receiving the third data packet, reporting the data in the third data packet to the PDCP entity or discarding the third data packet based on the local identifier and bearer identifier in the third data packet.

[0285] In a possible embodiment, the interface unit 801 is further configured to send request information to the relay device, where the request information is used to request to enable an indication function between a first terminal device and the relay device, and the indication function is a function of indicating the type of a data packet or the header format of a data packet; the processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device.

[0286] In a possible embodiment, the processing unit 802 enabling the indication function between the first terminal device and the relay device includes: receiving response information sent by the relay device for the request information, where the response information indicates to enable the indication function between the first terminal device and the relay device; enabling the indication function between the first terminal device and the relay device based on the response information.

[0287] In a possible embodiment, the interface unit 801 sending the request information to the relay device includes:

[0288] after establishing a first unicast connection and a second unicast connection with the relay device, sending the request information to the relay device, where the first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or,

[0289] sending a direct communication request message for establishing a second unicast connection to the relay device, where the direct communication request message carries the request information; or,

[0290] After establishing a first unicast connection with the relay device and before establishing a second unicast connection with the relay device, send request information to the relay device.

[0291] In a possible embodiment, the processing unit 802 is further configured to, after establishing a first unicast connection and a second unicast connection between the interface unit 801 and the relay device, enable an indication function between the first terminal device and the relay device, where the indication function is a function of indicating the type of data packet or indicating the packet header format of the data packet. The first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0292] The processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device when the interface unit 801 sends a direct communication request message for establishing a second unicast connection to the relay device; or,

[0293] The processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device when the interface unit 801 receives a direct communication acceptance message sent by the relay device for establishing a second unicast connection.

[0294] In a possible embodiment, the processing unit 802 reports the data in the third data packet to the PDCP entity or discards the third data packet based on the second indication information, including: determining that the third data packet comes from the relay device according to the source ID in the third data packet, and a first unicast connection and a second unicast connection are established between the first terminal device and the relay device, then determining the local identifier and the bearer identifier from the third data packet based on the second indication information; the first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; reporting the data in the third data packet to the corresponding PDCP entity or discarding the third data packet based on the local identifier and the bearer identifier in the third data packet.

[0295] In an implementation manner, when the communication device 800 is a relay device, where:

[0296] The interface unit 801 is configured to receive a first data packet sent by the first terminal device; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a terminal-to-terminal U2U relay data packet or a terminal-to-network U2N relay data packet, or indicates the packet header format of the first data packet; the processing unit 802 is configured to forward the data in the first data packet or discard the first data packet based on the first indication information.

[0297] In a possible embodiment, the first indication information is located in the adaptation layer header of the first data packet.

[0298] In a possible embodiment, the processing unit 802 forwards the data in the first data packet or discards the first data packet based on the first indication information, including: if the first indication information does not match the unicast connection for receiving the first data packet, the first data packet is discarded; if the first indication information matches the unicast connection for receiving the first data packet, the data in the first data packet is forwarded or the first data packet is discarded based on the local identifier and the bearer identifier in the first data packet.

[0299] In a possible embodiment, the interface unit 801 is further configured to receive a second data packet; the processing unit 802 is further configured to generate a third data packet based on the data in the second data packet, where the data in the third data packet is the same as the data in the second data packet; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the packet header format of the third data packet; the interface unit 801 is further configured to send the third data packet to the first terminal device.

[0300] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet.

[0301] In a possible embodiment, the interface unit 801 is further configured to receive request information sent by the first terminal device, where the request information is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of the data packet or the packet header format of the data packet; the processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device based on the request information.

[0302] In a possible embodiment, the interface unit 801 is further configured to send response information for the request information to the first terminal device, and the response information indicates that the indication function between the first terminal device and the relay device is enabled.

[0303] In a possible embodiment, the interface unit 801 receives the request information sent by the first terminal device, including:

[0304] After establishing a first unicast connection and a second unicast connection with the first terminal device, the request information sent by the first terminal device is received, where the first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0305] Receiving a direct communication request message for establishing a second unicast connection sent by the first terminal device, where the direct communication request message carries the request information; or,

[0306] After establishing a first unicast connection with the first terminal device and before establishing a second unicast connection with the first terminal device, request information sent by the first terminal device is received.

[0307] In a possible embodiment, the processing unit 802 is further configured to, after establishing a first unicast connection and a second unicast connection between the interface unit 801 and the first terminal device, enable an indication function between the first terminal device and the relay device, where the indication function is a function of indicating the type of a data packet or indicating the packet header format of a data packet. The first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or,

[0308] The processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device when the interface unit 801 receives a direct communication request message sent by the first terminal device for establishing a second unicast connection; or,

[0309] The processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device when the interface unit 801 sends a direct communication acceptance message for establishing a second unicast connection to the first terminal device.

[0310] In a possible embodiment, the processing unit 802 forwards the data in the first data packet or discards the first data packet based on first indication information, including: if it is determined based on the source ID in the first data packet that the first data packet comes from the first terminal device and a first unicast connection and a second unicast connection are established between the first terminal device and the relay device, then local identification and bearer identification are determined from the first data packet based on the first indication information; the first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; the data in the first data packet is forwarded or the first data packet is discarded based on the local identification and the bearer identification in the first data packet.

[0311] In an implementation manner, when the communication device 800 is the first terminal device, where:

[0312] The interface unit 801 is configured to receive a third data packet sent by the relay device; the third data packet carries second indication information, where the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the packet header format of the third data packet;

[0313] The processing unit 802 is configured to report the data in the third data packet to a Packet Data Convergence Protocol (PDCP) entity based on the second indication information or discard the third data packet.

[0314] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet.

[0315] In a possible embodiment, the processing unit 802 reports the data in the third data packet to the PDCP entity or discards the third data packet based on the second indication information, including: if the second indication information does not match the unicast connection for receiving the third data packet, the third data packet is discarded; if the second indication information matches the unicast connection for receiving the third data packet, the data in the third data packet is reported to the PDCP entity or the third data packet is discarded based on the local identifier and the bearer identifier in the third data packet.

[0316] In a possible embodiment, the interface unit 801 is further configured to send a request message to the relay device, where the request message is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of the data packet or the header format of the data packet; the processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device.

[0317] In a possible embodiment, the processing unit 802 enables the indication function between the first terminal device and the relay device, including:

[0318] Receiving a response message for the request message sent by the relay device, where the response message indicates to enable the indication function between the first terminal device and the relay device; enabling the indication function between the first terminal device and the relay device based on the response message.

[0319] In a possible embodiment, the interface unit 801 sends a request message to the relay device, including:

[0320] After establishing a first unicast connection and a second unicast connection with the relay device, sending a request message to the relay device, where the first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0321] Sending a direct communication request message for establishing a second unicast connection to the relay device, where the direct communication request message carries the request message; or,

[0322] After establishing a first unicast connection with the relay device and before establishing a second unicast connection with the relay device, sending a request message to the relay device.

[0323] In a possible embodiment, after the processing unit 802 further establishes a first unicast connection and a second unicast connection between the interface unit 801 and the relay device, the processing unit 802 enables an indication function between the first terminal device and the relay device. The indication function is a function of indicating the type of data packet or the header format of the data packet. The first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; or,

[0324] The processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device when the interface unit 801 sends a direct communication request message for establishing a second unicast connection to the relay device; or,

[0325] The processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device when the interface unit 801 receives a direct communication acceptance message sent by the relay device for establishing a second unicast connection.

[0326] In a possible embodiment, the processing unit 802 reports the data in the third data packet to the PDCP entity or discards the third data packet based on the second indication information, including: determining that the third data packet comes from the relay device according to the source ID in the third data packet, and a first unicast connection and a second unicast connection are established between the first terminal device and the relay device, then determining the local identifier and the bearer identifier from the third data packet based on the second indication information; the first unicast connection is used for the first terminal device to communicate with the network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with the second terminal device through the relay device; reporting the data in the third data packet to the corresponding PDCP entity or discarding the third data packet based on the local identifier and the bearer identifier in the third data packet.

[0327] In an implementation manner, when the communication device 800 is a relay device, where:

[0328] The interface unit 801 is configured to receive a second data packet;

[0329] The processing unit 802 is configured to generate a third data packet based on the data in the second data packet, and the data in the third data packet is the same as the data in the second data packet; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the header format of the third data packet;

[0330] The interface unit 801 is further configured to send the third data packet to the first terminal device.

[0331] In a possible embodiment, the second indication information is located in the adaptation layer header of the third data packet.

[0332] In a possible embodiment, the interface unit 801 is further configured to receive request information sent by a first terminal device, where the request information is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of a data packet or indicating the header format of a data packet; the processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device based on the request information.

[0333] In a possible embodiment, the interface unit 801 is further configured to send response information for the request information to the first terminal device, where the response information indicates to enable the indication function between the first terminal device and the relay device.

[0334] In a possible embodiment, the interface unit 801 receiving the request information sent by the first terminal device includes:

[0335] After establishing a first unicast connection and a second unicast connection with the first terminal device, receiving the request information sent by the first terminal device, where the first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or,

[0336] Receiving a direct communication request message for establishing a second unicast connection sent by the first terminal device, where the direct communication request message carries the request information; or,

[0337] After establishing a first unicast connection with the first terminal device and before establishing a second unicast connection with the first terminal device, receiving the request information sent by the first terminal device.

[0338] In a possible embodiment, the processing unit 802 is further configured to, after establishing a first unicast connection and a second unicast connection between the interface unit 801 and the first terminal device, enable the indication function between the first terminal device and the relay device, where the indication function is a function of indicating the type of a data packet or indicating the header format of a data packet, the first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or,

[0339] The processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device when the interface unit 801 receives a direct communication request message for establishing a second unicast connection sent by the first terminal device; or,

[0340] The processing unit 802 is further configured to enable the indication function between the first terminal device and the relay device when the interface unit 801 sends a direct communication acceptance message for establishing a second unicast connection to the first terminal device.

[0341] Such asFigure 9 As shown, a communication device 900 provided by an embodiment of the present application is used to implement the functions of the above-mentioned first terminal device or relay device. The device may be a communication device or a device used in a communication device. The communication device may be a first terminal device or a relay device. The device used in the communication device may be a chip system or a chip in the communication device. Among them, the chip system may be composed of chips or may include chips and other discrete devices.

[0342] The communication device 900 includes at least one processor 910, which is used to implement the processing functions of the device (such as a relay device or a first terminal device) in the method provided by the embodiment of the present application.

[0343] Optionally, the communication device 900 may further include a communication interface 920, which is used to implement the transceiver operations of the device (such as a relay device or a first terminal device) in the method provided by the embodiment of the present application. In the embodiment of the present application, the communication interface may be a transceiver, a circuit, a bus, a module or other types of communication interfaces, and is used to communicate with other devices through a transmission medium. For example, the communication interface 920 is used for the device in the communication device 900 to communicate with other devices. The processor 910 uses the communication interface 920 to send and receive data, and is used to implement the method described in the above method embodiment. As Figure 9 shown, the communication interface 920 may be located inside the communication device 900 or outside the communication device 900, which is not limited in the embodiment of the present application.

[0344] Optionally, the communication device 900 may further include at least one memory 930, which is used to store program instructions and / or data. The memory 930 is coupled to the processor 910. The coupling in the embodiment of the present application is an indirect coupling or communication connection between devices, units or modules, and may be electrical, mechanical or other forms, and is used for information interaction between devices, units or modules. The processor 910 may cooperate with the memory 930. The processor 910 may execute the program instructions stored in the memory 930. At least one of the at least one memories may be included in the processor 910. Or, the at least one memory may be located inside the communication device 900 and outside the processor 910. Or, the at least one memory may be located outside the communication device 900, which is not limited in the embodiment of the present application.

[0345] In the embodiment of the present application, the specific connection medium between the above-mentioned communication interface 920, processor 910 and memory 930 is not limited. The embodiment of the present application is Figure 9 illustrated with the memory 930, processor 910 and communication interface 920 connected through a bus, and the bus is Figure 9is represented by a thick line, and the connection manners between other components are only for illustrative purposes and are not limited thereto. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 9 it is only represented by a thick line in the figure, but it does not mean that there is only one bus or one type of bus.

[0346] When the communication device 900 is specifically a device for a device (such as a relay device or a first terminal device), for example, when the communication device 900 is specifically a chip or a chip system, what the communication interface 920 outputs or receives can be a baseband signal. When the communication device 900 is specifically a device (such as a relay device or a first terminal device), what the communication interface 920 outputs or receives can be a radio frequency signal. In the embodiments of the present application, the processor can be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0347] It should be noted that the above-mentioned communication interface 920 can be used to execute the functions of the foregoing interface unit 801, and the above-mentioned processor 910 can be used to execute the functions of the foregoing processing unit 802, which will not be elaborated herein.

[0348] When the above-mentioned communication device is a chip applied to a first terminal device, the first terminal device chip implements the functions of the first terminal device in the above method embodiments, and the first terminal device chip receives information from other network elements; or, the first terminal device chip sends information to other network elements.

[0349] When the above-mentioned communication device is a chip applied to a relay device, the relay device chip implements the functions of the relay device in the above method embodiments. The relay device chip receives information from other network elements; or, the relay device chip sends information to other network elements.

[0350] It can be understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0351] The method steps in the embodiments of the present application may be implemented in a hardware manner, or may be implemented by a processor executing software instructions. The software instructions may be composed of corresponding software modules, and the software modules may be stored in a random access memory (RAM), flash memory, read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, hard disks, removable hard disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and the storage medium may be located in the ASIC. In addition, the ASIC may be located in the relay device or the first terminal device. Of course, the processor and the storage medium may also exist as discrete components in the first terminal device or the relay device.

[0352] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer program or instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server integrating one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it can also be an optical medium, such as a DVD; or it can be a semiconductor medium, such as a solid state disk (SSD).

[0353] In various embodiments of the present application, without special instructions and logical conflicts, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0354] It can be understood that the various numerical numbers involved in the embodiments of the present application are only for the convenience of description and do not limit the scope of the embodiments of the present application. The magnitudes of the serial numbers of the above processes do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic.

[0355] The embodiments of the present application further provide a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed, the method executed by the first terminal device or the relay device in the above method embodiments is implemented.

[0356] The embodiments of the present application further provide a computer program product, which includes a computer program. When the computer program is executed, the method executed by the first terminal device or the relay device in the above method embodiments is implemented.

[0357] The embodiments of the present application further provide a communication system, which includes a first terminal device or a relay device. Among them, the first terminal device is used to execute the method executed by the first terminal device in the above method embodiments. The relay device is used to execute the method executed by the relay device in the above method embodiments.

[0358] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that this application is not limited by the described action sequence, because according to this application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0359] The descriptions of the embodiments provided in this application can be referred to each other. The descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. For the convenience and conciseness of description, for example, the functions and steps performed by the various devices and equipment provided in the embodiments of this application can be referred to the relevant descriptions of the method embodiments of this application. The method embodiments can also refer to, combine with, or cite each other among the device embodiments.

[0360] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of this application, not to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A data packet transmission method, characterized in that, the method includes: A first terminal device generates a first data packet; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a terminal-to-terminal U2U relay data packet or a terminal-to-network U2N relay data packet, or indicates the header format of the first data packet; The first terminal device sends the first data packet to a relay device.

2. The method according to claim 1, characterized in that, the first indication information is located in the adaptation layer header of the first data packet.

3. The method according to claim 1 or 2, characterized in that, the method further includes: The first terminal device receives a third data packet sent by the relay device; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the header format of the third data packet; The first terminal device reports the data in the third data packet to a Packet Data Convergence Protocol (PDCP) entity or discards the third data packet based on the second indication information.

4. The method according to claim 3, characterized in that, the second indication information is located in the adaptation layer header of the third data packet.

5. The method according to claim 3 or 4, characterized in that, the first terminal device reporting the data in the third data packet to the PDCP entity or discarding the third data packet based on the second indication information includes: If the second indication information does not match the unicast connection for receiving the third data packet, then discard the third data packet; If the second indication information matches the unicast connection for receiving the third data packet, then report the data in the third data packet to the PDCP entity or discard the third data packet based on the local identifier and bearer identifier in the third data packet.

6. The method according to any one of claims 1 to 5, characterized in that, the method further includes: The first terminal device sends request information to the relay device, and the request information is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of a data packet or indicating the header format of a data packet; The first terminal device enables the indication function between the first terminal device and the relay device.

7. The method according to claim 6, characterized in that, the first terminal device enabling the indication function between the first terminal device and the relay device includes: The first terminal device receives response information for the request information sent by the relay device, and the response information indicates to enable the indication function between the first terminal device and the relay device; The first terminal device enables the indication function between the first terminal device and the relay device based on the response information.

8. The method according to claim 6 or 7, characterized in that, the first terminal device sending request information to the relay device includes: After establishing a first unicast connection and a second unicast connection between the first terminal device and the relay device, the first terminal device sends request information to the relay device. The first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or, The first terminal device sends a direct communication request message for establishing a second unicast connection to the relay device, and the direct communication request message carries the request information; or, After establishing a first unicast connection between the first terminal device and the relay device and before establishing a second unicast connection between the first terminal device and the relay device, the first terminal device sends request information to the relay device.

9. The method according to any one of claims 1 to 5, wherein, the method further comprises: After establishing a first unicast connection and a second unicast connection between the first terminal device and the relay device, the first terminal device enables an indication function between the first terminal device and the relay device. The indication function is a function of indicating the type of a data packet or indicating the packet header format of a data packet. The first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or, When the first terminal device sends a direct communication request message for establishing a second unicast connection to the relay device, the first terminal device enables the indication function between the first terminal device and the relay device; or, When the first terminal device receives a direct communication acceptance message for establishing a second unicast connection sent by the relay device, the first terminal device enables the indication function between the first terminal device and the relay device.

10. The method according to claim 3 or 4, wherein, The first terminal device reporting the data in the third data packet to a PDCP entity or discarding the third data packet based on the second indication information includes: The first terminal device determines that the third data packet comes from the relay device according to the source ID in the third data packet. If a first unicast connection and a second unicast connection are established between the first terminal device and the relay device, the first terminal device determines a local identifier and a bearer identifier from the third data packet based on the second indication information. The first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; The first terminal device reports the data in the third data packet to the corresponding PDCP entity or discards the third data packet based on the local identifier and the bearer identifier in the third data packet.

11. A data packet transmission method, wherein, the method comprises: The relay device receives a first data packet sent by a first terminal device; the first data packet carries first indication information, and the first indication information indicates that the type of the first data packet is a terminal-to-terminal U2U relay data packet or a terminal-to-network U2N relay data packet, or indicates the header format of the first data packet. The relay device forwards the data in the first data packet or discards the first data packet based on the first indication information.

12. The method according to claim 11, wherein, the first indication information is located in the adaptation layer header of the first data packet.

13. The method according to claim 11 or 12, wherein, the relay device forwards the data in the first data packet or discards the first data packet based on the first indication information, including: if the first indication information does not match the unicast connection for receiving the first data packet, the first data packet is discarded; if the first indication information matches the unicast connection for receiving the first data packet, the data in the first data packet is forwarded or the first data packet is discarded based on the local identifier and bearer identifier in the first data packet.

14. The method according to any one of claims 11 to 13, wherein, the method further includes: the relay device receives a second data packet; the relay device generates a third data packet based on the data in the second data packet, and the data in the third data packet is the same as the data in the second data packet; the third data packet carries second indication information, and the second indication information indicates that the type of the third data packet is a U2U relay data packet or a U2N relay data packet, or indicates the header format of the third data packet; the relay device sends the third data packet to the first terminal device.

15. The method according to claim 14, wherein, the second indication information is located in the adaptation layer header of the third data packet.

16. The method according to any one of claims 11 to 15, wherein, the method further includes: the relay device receives request information sent by the first terminal device, and the request information is used to request to enable an indication function between the first terminal device and the relay device, and the indication function is a function of indicating the type of a data packet or indicating the header format of a data packet; the relay device enables the indication function between the first terminal device and the relay device based on the request information.

17. The method according to claim 16, wherein, the method further includes: the relay device sends response information for the request information to the first terminal device, and the response information indicates that the indication function between the first terminal device and the relay device is enabled.

18. The method according to claim 16 or 17, wherein, the relay device receives the request information sent by the first terminal device, including: After establishing a first unicast connection and a second unicast connection with the first terminal device, the relay device receives request information sent by the first terminal device. The first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or, The relay device receives a direct communication request message sent by the first terminal device for establishing a second unicast connection, where the direct communication request message carries the request information; or, After establishing a first unicast connection with the first terminal device and before establishing a second unicast connection with the first terminal device, the relay device receives request information sent by the first terminal device.

19. The method according to any one of claims 11 to 15, wherein, the method further includes: After establishing a first unicast connection and a second unicast connection with the first terminal device, the relay device enables an indication function between the first terminal device and the relay device. The indication function is a function of indicating the type of data packet or indicating the packet header format of the data packet. The first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; or, When the relay device receives a direct communication request message sent by the first terminal device for establishing a second unicast connection, the relay device enables the indication function between the first terminal device and the relay device; or, When the relay device sends a direct communication acceptance message for establishing a second unicast connection to the first terminal device, the relay device enables the indication function between the first terminal device and the relay device.

20. The method according to claim 11 or 12, wherein, The relay device forwards the data in the first data packet or discards the first data packet based on the first indication information, including: If it is determined based on the source ID in the first data packet that the first data packet comes from the first terminal device and a first unicast connection and a second unicast connection are established between the first terminal device and the relay device, then the relay device determines a local identifier and a bearer identifier from the first data packet based on the first indication information; the first unicast connection is used for the first terminal device to communicate with a network device through the relay device, and the second unicast connection is used for the first terminal device to communicate with a second terminal device through the relay device; The relay device forwards the data in the first data packet or discards the first data packet based on the local identifier and the bearer identifier in the first data packet.

21. A communication device, wherein, it includes a unit for executing the method according to any one of claims 1 to 10, or includes a unit for executing the method according to any one of claims 11 to 20.

22. A communication device, wherein, Comprising a processor and a memory, the processor and the memory being coupled, the processor being configured to implement the method according to any one of claims 1 to 10, or the processor being configured to implement the method according to any one of claims 11 to 20.

23. A chip, Characterized in that it comprises a processor and an interface, the processor and the interface being coupled; the interface is used for receiving or outputting signals, and the processor is used for executing code instructions to cause the method according to any one of claims 1 to 10 to be executed, or to cause the method according to any one of claims 11 to 20 to be executed.

24. A computer-readable storage medium, Characterized in that the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are called by the computer, the computer is caused to execute the method according to any one of claims 1 to 10 above, or the computer is caused to execute the method according to any one of claims 11 to 20 above.

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